Would that be 12 January Old Style or New Style? (And are you sure the year number changed on 1 January in the region where that text was written or published?)

Would that be 12 January Old Style or New Style? (And are you sure the year number changed on 1 January in the region where that text was written or published?) http://en.wikipedia.org/wiki/Old_Style_and_New_Style_dates http://en.wikipedia.org/wiki/Old_Style_and_New_Style_dates